package qlsl.androiddesign.view.commonview.firstsort;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.graphics.drawable.ColorDrawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TextView;

/**
 * 通讯录页面侧边栏滑动定位的字母栏
 * @author xiaopeixian
 * @data 2015-9-17
 */
public class SideBar extends View {
	// 触摸事件  
    private OnTouchingLetterChangedListener onTouchingLetterChangedListener;  
    // 26个字母  
    public static String[] b = {"#", "A", "B", "C", "D", "E", "F", "G", "H", "I",  
            "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",  
            "W", "X", "Y", "Z" };  
    private int choose = -1;// 选中  
    private Paint paint = new Paint();  
  
    private TextView mTextDialog;  
  
    /** 
     * 为SideBar设置显示字母的TextView 
     * @param mTextDialog 
     */  
    public void setTextView(TextView mTextDialog) {  
        this.mTextDialog = mTextDialog;  
    }  
  
  
    public SideBar(Context context, AttributeSet attrs, int defStyle) {  
        super(context, attrs, defStyle);  
    }  
  
    public SideBar(Context context, AttributeSet attrs) {  
        super(context, attrs);  
    }  
  
    public SideBar(Context context) {  
        super(context);  
    }  
  
    /** 
     * 重写这个方法 
     */  
    protected void onDraw(Canvas canvas) {  
        super.onDraw(canvas);  
        // 获取焦点改变背景颜色.  
        int height = getHeight();// 获取对应高度  
        int width = getWidth(); // 获取对应宽度  
        int singleHeight = height / b.length;// 获取每一个字母的高度  
  
        for (int i = 0; i < b.length; i++) {  
            paint.setColor(Color.parseColor("#727272"));  
            // paint.setColor(Color.WHITE);  
            paint.setTypeface(Typeface.DEFAULT_BOLD);  
            paint.setAntiAlias(true);  
            paint.setTextSize(20);  
            // 选中的状态  
            if (i == choose) {  
                paint.setColor(Color.parseColor("#3399ff"));  
                paint.setFakeBoldText(true);  
            }  
            // x坐标等于中间-字符串宽度的一半.  
            float xPos = width / 2 - paint.measureText(b[i]) / 2;  
            float yPos = singleHeight * i + singleHeight;  
            canvas.drawText(b[i], xPos, yPos, paint);  
            paint.reset();// 重置画笔  
        }  
  
    }  
  
    @SuppressWarnings("deprecation")
	@Override  
    public boolean dispatchTouchEvent(MotionEvent event) {  
        final int action = event.getAction();  
        final float y = event.getY();// 点击y坐标  
        final int oldChoose = choose;  
        final OnTouchingLetterChangedListener listener = onTouchingLetterChangedListener;  
        final int c = (int) (y / getHeight() * b.length);// 点击y坐标所占总高度的比例*b数组的长度就等于点击b中的个数.  
  
        switch (action) {  
        case MotionEvent.ACTION_UP:  
            setBackgroundDrawable(new ColorDrawable(0x00000000));  
            choose = -1;//  
            invalidate();  
            if (mTextDialog != null) {  
                mTextDialog.setVisibility(View.INVISIBLE);  
            }  
            break;  
  
        default:  
            setBackgroundColor(Color.parseColor("#10000000"));
            if (oldChoose != c) {  
                if (c >= 0 && c < b.length) {  
                    if (listener != null) {  
                        listener.onTouchingLetterChanged(b[c]);  
                    }  
                    if (mTextDialog != null) {  
                        mTextDialog.setText(b[c]);  
                        mTextDialog.setVisibility(View.VISIBLE);  
                    }  
                      
                    choose = c;  
                    invalidate();  
                }  
            }  
  
            break;  
        }  
        return true;  
    }  
  
    /** 
     * 向外公开的方法 
     *  
     * @param onTouchingLetterChangedListener 
     */  
    public void setOnTouchingLetterChangedListener(  
            OnTouchingLetterChangedListener onTouchingLetterChangedListener) {  
        this.onTouchingLetterChangedListener = onTouchingLetterChangedListener;  
    }  
  
    /** 
     * 接口 
     *  
     * @author coder 
     *  
     */  
    public interface OnTouchingLetterChangedListener {  
        public void onTouchingLetterChanged(String s);  
    }  
  
}
